Microfilm reproduction machine



D c- 5, 1970 0.12. STOKES ETAL 7,5

MICROFILM REPRODUCTION MACHINE 2 Sheets-Sheet 1 Filed Nov. 4, 1965ATTORNEY Dec. 15, 1970 D. R. STOKES ETAL 4 v 3,547,533

. -MICROFILM REPRODUCTION MACHINE Filed Nov. 4, 1965 2 Sheets-Sheet 2NVENTORS 1 DAVID R.STOKE$ BY GILBERT A. ASER ATTORNEY United StatesPatent 3,547,533 MICROFILM REPRGDUCTKON MACHINE David R. Stokes,Webster, and Gilbert A. Aser, Rochester,

N.Y., assignors to Xerox Corporation, Rochester, N.Y.,

a corporation of New York Filed Nov. 4, 1965, Ser. No. 506,386 Int. Cl.G03g /04 US. Cl. 355-3 9 Claims ABSTRACT OF THE DISCLOSURE Anelectrostatic reproduction machine having a first projector forproducing an enlarged image of a microfilm frame upon a Fresnel lens,and a second projection means adapted to project that image on theFresnel lens as an object and to image it on an electrostatic surface.

This invention relates in general to electrostatographic copying and inparticular to improved apparatus for reproducing electrostatographicallyfrom microfilm originals. More specifically, the invention relates to animproved xerographic apparatus for causing microfilm, whether in theform of a single frame mounted in a data processing card or in the formof roll film, to be xerographically reproduced on conventionalxerographic machines.

Electrostatography encompasses the entire field of forming and utilizinglatent electrostatic charge patterns to record and reproduce patterns inviewable form. Xerography employs a photoconductive insulating mediumand radiation to form the latent electrostatic images.

In the process of xerography, a xerographic plate comprising a layer ofphotoconductive insulating material on a conductive backing is given auniform electric charge over its surface and is then exposed to thesubject matter to be reproduced, usually by conventional projectiontechniques. This exposure discharges the plate areas in accordance withthe radiation intensity which reaches them and thereby creates anelectrostatic latent image on or in the plate coating.

Development of the image is effected with developer material ordevelopers which comprise, in general, a mixture of a suitable pigmentedor dyed electroscopic powder, hereinafter referred to as toner, and agranular carrier material, which later functions to carry and togenerate triboelectric charges on the toner. In the development of theimage, the toner powder is brought into surface contact with thephotoconductive coating of the xerographic plate and is held thereonelectrostatically in a pattern corresponding to the electrostatic latentimage. Thereafter, the developed xerographic image is usuallytransferred to a support or transfer material to which it may be fixedby any suitable means.

Since the disclosure of the basic concept of xerography, a variety ofmachines and devices have been proposed to incorporate such teachings ina manner to form copy xerographically on a commercial basis. For themost part, each of such devices has been specifically designed to thesolution of a particular reproduction problem, and for the most part,has been limited to the particular use intended. Thus, for example,machines are presently in wide commercial use for the continuoushigh-speed enlargement of microfilm in roll form, and for reproducingfrom opaque originals.

One of the most commercially successful xerographic machines is thatdisclosed in Mayo Pat. 3,062,109, issued on Nov. 6, 1962. This machineis used for reproducing from opaque originals which are placed on aplaten on the top of its desk-like shape. As useful as this machine maybe, as evidenced by its commercial acceptance, it

cannot be used to reproduce xerographic copies from microfilm, althoughmany establishments using this machine have occasion to reproduce copiesfrom their microfilm files. The major problem in the development of suchan attachment is the production of a suitable image in the plane of theplaten of the electrostatic reproducing machine with an adequatequantity of uniform illumination to enable the existing system toproduce an acceptable copy.

This apparatus is intended to be used as a microfilm attachment for astandard desk-type electrostatic machine copier, thus providing thecapability of producing a hard copy from microfilm as well as from theconventional document copy. There have, of course, been machines forxerographically reproducing from microfilm originals either in rolls orsingle frame mounted in data processing cards, but these machines werenot portable and capable of attachment to other existing xerographicreproducing machines. Although these machines make excellent copies andhave achieved substantial commercial success, they all scanned themicrofilm original during the exposure step of the xerographic process.This necessitated complicated equipment, automatic devices; programmingmeans and elaborate timing equipment for synchronizing the relativemovement of the microfilm original scanning device and the xerographicdrum upon which the electrostatic image was to be formed. Such a devicemay be seen, for example, in Hunt Pat. No. 3,078,770 issued Feb. 6,1963, and Rutkus Pat. No. 3,137,202 issued June 16, 1964.

It is therefore an object of this invention to improve theelectrostatographic reproducing apparatus for microdata image copying.

Another object of this invention is to make portable apparatus for usein existing xerographic reproducing machines for reproducing microfilmonto single sheet transfer copies.

A further object is to xerographically reproduce a full frame ofmicrofilm with no movement of the film relative to a fixed optical axis.

Another object of this invention is to employ inexpensive and easilyfabricated optical equipment to xeographically reproduce from microfilmoriginals.

These and other objects of the invention are attained by means of anapparatus for projecting image rays from miniaturized input for visualviewing to a light-receiving means of an electrostatic reproducingapparatus in order to make xerographic copies of the original projectedto the platen.

For a better understanding on the invention, as well as other objectsand further features thereof, reference is had to the following detaileddescription of the invention to be read in conjunction with theaccompanying drawings, wherein:

FIG. 1 illustrates schematically an embodiment of a microfilm attachmentfor projecting viewable images on the platen of an electrostatic copyingmachine in conjunction with a preferred embodiment of the xerographicapparatus adapted for continuous and automatic operation andincorporating an optical scanning mechanism;

FIG. 2 is a schematic perspective view of the microfilm attachment andxerographic reproducing apparatus showing optical axis and scanningfeatures;

Referring now to the drawings wherein like numerals designate likeelements, there is shown schematically in FIG. 1 a microfilmelectrostatographic copying apparatus in the environment of axerographic apparatus incorporated into an automatic machine.

The xerographic apparatus comprises a xerographic plate including aphotoconductive layer on a conductive backing and formed in the shape ofa drum, generally designated by the numeral 20. The drum is mounted on ashaft journaled on a frame to rotate in the direction indicated by thearrow to cause the drum surface sequentially to pass a plurality ofxerographic processing stations.

For the purpose of the present disclosure, the several xerographicprocessing stations in the path of movement of the drum surface may bedescribed functionally, as follows:

A charging station, preferably located as indicated by referencecharacter A, at which a uniform electrostatic charge is deposited on thephotoconductive layer of the xerographic drum.

Next subsequent thereto in the path of motion of the xerographic drum isexposure station B at which a light or radiation pattern of copy to bereproduced is projected onto the drum surface to dissipate the drumcharge in the exposed areas thereof. Thereby, a latent electrostaticimage of copy to be produced is formed.

Adjacent to the exposure station is a developing station C in whichthere is positioned a developer apparatus including a container 22having a lower sump portion for accumulating developer material 24. Astoner powder images are formed, additional toner particles must be supplied to the developing material in proportion to the amount of tonerdeposited on the drum. For this purpose, a toner dispenser, generallydesignated 26, is used to replenish toner to the developing material.

Positioned next adjacent to the developing station is the image transferstation D at which the xerographic powder image is electrostaticallytransferred from the drum surface to a transfer material or supportsurface. This is accomplished here by the corona transfer device 28.

Immediately subsequent to transfer is a stripping device, generallydesignated 30, for removing the transfer material from the drum surface.After stripping, the powder image may be fused to the transfer materialby the fuser 32 and then transported to copy holder 34.

The final station E is a drum cleaning and discharge station at whichthe drum surface is brushed to remove residual toner particles remainingafter image transfer, and at which drum surface is exposed to arelatively bright light source to effect substantially completedischarge of any residual electrostatic charge remaining thereon.

For a more complete and detailed description of the automaticxerographic apparatus, see Mayo et al. Pat. No. 3,062,109, issued Nov.6, 1962.

At the exposure station B, and more specifically relating to theimprovement in microfilm imaging for electrostatographic reproduction,is the microfilm enlarging and imaging apparatus necessary to form axerographically reproducible image on drum 20 from platen 2. This isaccomplished by means of a projection system adapted to converge thelight rays diverging from an enlarging, objective lens to form anenlarged and uniformly lighted image at its focal plane with the rays oflight converging therefrom. The light source for this system is a lamp 4and condenser lens 6 causing light to project through a frame ofmicrofilm held in, for example, microfilm roller 8, and throughobjective lens 10 to be enlarged thereby. The resulting image light raysproject through a light gathering means such as a Fresnel lens 12 to beimaged on a translucent material 14, which can be any of a variety ofmaterials, for example, frosted glass, etc., placed approximately at thefocal plane of the objective lens system and directly on the platen 2.The. platen defines the object plane of the xerographic reproducingsystem. The image thereon is protected from extraneous light by lightshield and container 16 adapted to position the microfilm projectionsystem such that the image falls substantially over platen 2. The lightsource is further directed by reflector 3 and the lamp 4 is cooled byblower 5.

The container 16 further serves as the housing for the portablemicrofilm enlarging and imaging apparatus. It is adapted to fixedlycontain the Fresnel lens and the translucent material as well as theentire projection system for enlarging and imaging the microfilm. Thus,the entire microfilm projection apparatus is portable and may be easilyattached to or detached from an existing xerographic reproducing machinewithout necessitating any modifications in such machine for acceptingthis apparatus.

The system, therefore, directs an enlarged image of micro-data obtainedfrom the microfilm original to a translucent material on the platen ofthe xerographic machine through a light gathering device, such as aFresnel lens, to insure the converging of the light rays at the exposurestation of the xerographic machine. The xerographic machine may thenscan the image on its platen to produce a latent electrostatic image onthe xerographic drum 20- Referring now to FIG. 2, the scanning of thedata which is imaged in position on a fixed platen is accomplished bymeans of a movable lens systemwhich is moved relative to the platen intimed relation to the movement of the xerographic plate or drum. Thereis provided a light shield 42 having an aperture therein extendingacross the entire image on the platen. Although this shield mayeliminate extraneous light from the scanning lens 50, it is not anessential element for obtaining acceptable copies. It is includedbecause many commercially successful existing xerographic machinescapable of interaction with this portable microfilm unit contain such ashield in conjunction with their own illuminating systems.

A fixed object mirror 48 mounted below the fixed platen reflects theimage rays of the data thereon through the lens 50 of the lens systemonto an image mirror 52 which in turn reflects the image rays onto thexerographic drum at the slot in a fixed exposure slit plate 46positioned adjacent to the xerographic drum. This slit 46 preventsextraneous light from reaching the drum and further serves to provide auniform exposure of the micro-data to be reproduced.

The light shield and the laterally movable lens system are connected bya pair of cables 54 and 56 to the pulleys 58 of the scan controlmechanism in such timed relation that the micro-data image appearing atthe platen is fully exposed during the scan, through the aperture of thelight shield, through the lens, and through the exposure slit to thexerographic plate or drum. For a more detailed and complete descriptionof a preferred embodiment of a xerographic scanning apparatus, seeRutkus et al. Pat. No. 3,062,095 issued Nov. 6, 1962.

The system, as shown in FIG. 2, for xerographically reproducing theimage formed on translucent material 14 approximately at the focal pointof platen 2 is shown as folded since that is the most convenient mannerof including it in an automatic xerographic machine such as that whichwas schematically shown in FIG. 1. As was shown in FIG. 1, the imagerays leaving the first projection system at objective lens 1 0 diverge,causing an enlargement of the image of the microfilm. However, the lightrays striking the translucent material on which the image is formed areconverging rays such that the light rays are substantially directed tothe xerographic scanning lens 50 through exposure plate 42. This iscaused by the Fresnel lens, or a suitable field lens. Without such alens, the light rays forming the image on the translucent material atthe platen would continue through in the diverging manner that theyleave the objective lens. Much of these light rays are unuseable to thexerographic reproducing system viewing the image formed on its objectiveplane since only that portion of the light rays passing through thexerographic scanning lens 50 will dissipate the charge on the drumforming a latent electrostatic pattern comparable to the image on platen2. Lamp 4 produces light of sufficient intensity to accomplish theproduction of the latent image.

From the foregoing, it will be apparent that the platen is in the imageplane of the projection system projecting the microfilm image andfurther serves as the object plane for the projection system of thexerographic reproducing apparatus.

The Fresnel lens is placed a slight distance above the focal plane ofthe xerographic reproducing system so that the gratings of the lens arenot reproduced as lines on the xerographic copy. This distance, however,is such that there is sufficient-imaging at the xerographic drum so asto permit production of copies having acceptable resolution.

While the invention has been described with reference to the structuresdisclosed herein, it is not confined to the details set forth; and thisapplication is intended to cover such modifications or changes as maycome within the purposes of the improvements or the scope of thefollowing claims.

What is claimed is:

1. A reproducing apparatus for electrostatographically reproducing amicrofilm object, such apparatus having an electrostatographic surfaceadapted for receiving image rays of the microfilm object and processingapparatus for reproducing copies therefrom, comprising first projectionmeans for projecting diverging image rays of the microfilm object,

an image receiving member partially approximately at the focal plane ofsaid first projection means and arranged to receive enlarged microfilmimages from said first projection means, said image receiving memberincluding a Fresnel lens positioned slightly out of the focal plane ofsaid first projection means, and

second projection means adapted to direct the enlarged image on saidreceiving member simultaneously, as the same is produced, to theelectrostatographic surface at a large magnification compared to themicrofilm object and thereby effect the reproduction of enlarged copiesof the microfilm images by the processing system.

2. The apparatus of claim 1, said image receiving member comprising aFresnel lens spaced from the focal plane of the first projection meansand a translucent material approximately at the focal plane of saidsecond projection means.

3. The apparatus of claim 1, said second projection system adapted toscan the enlarged micro-data image on said image receiving member and toproject the enlarged micro-data image rays thereon to theelectrostatographic surface and thereby effect the reproduction ofenlarged copies of the micro-data images by the processing system.

4. The apparatus of claim 1, said first projection means including alamp means and an enlarging lens system and having means associatedtherewith for supporting microfilm for projection of images therein, andadapted to present an illuminated, enlarged representation of eachmicrofilm image; said second projection means adapted 6 to scan theimage on said image receiving member and to project said image raysthereon to the electrostatographic surface and thereby effect thereproduction of enlarged copies of the images by the processingapparatus.

5. The apparatus of claim 1 wherein said first projection means and saidimage receiving member have further associated therewith a lightshielding housing adapted to maintain said first projection means andsaid receiving member and adapted to removably position said memberapproximately at the focal plane of said first projection means.

6. A reproducing apparatus including a platen to which an object isapplied during copying thereof,

a photosensitive surface,

first projection means adapted to project the light rays from an objectpositionable at said platen to the photosensitive surface,

processing means adapted to be active upon the exposed photosensitivesurface to form copies thereon of the object at the platen,

an image receiving member applicable to the platen and including aFresnel lens,

second projection means adapted to present image light rays at theremovable image receiving member,

a light shielding housing removably positionable on the platen andenclosing and securing said image receiving means and said secondprojection means in a spaced apart relation to each other with at leasta portion of the former approximately in the image plane of the latter.

7. The apparatus of claim 6 wherein said light shielding housing isadapted to maintain said second projection means and said receivingmember in a spaced apart relationship, said housing including spacermeans attached thereto near said receiving member to maintain saidFresnel lens positioned slightly spaced from the focal plane of saidsecond projection means.

8. The apparatus of claim 6 wherein the object is positionable on thesame surface of said platen as is said image receiving member.

9. The apparatus of claim 6 wherein said first projection means isadapted to scan the platen.

References Cited UNITED STATES PATENTS 2,174,931 10/1939 Terry 35247X2,959,095 11/1960 Magnusson l.7X 3,174,417 3/1965 Sauer 9549 3,062,11011/1962 Shepardson 95-1.7

JOHN M. HORAN, Primary Examiner US. Cl. X.R. 355-18

